The present invention relates to a diving face mask and more particularly to a diving face mask improved to facilitate lens exchange.
Diving face masks are well known which typically comprises a pair of front lenses, a main frame consisting of a lens frame into which the respective lenses can be fitted at a front portion of the mask and a tubular facial skirt adapted to be held in close contact with a wearer's face at a rear portion of the mask, and a strap adapted to be put around the wearer's head. For example, JP1996-107948A discloses such diving face mask wherein the lens frame comprises an annular outer frame including a pair of lens holders and an annular inner frame adapted to be snap-engaged around respective inner peripheral walls of the lens holders from front after the lenses have been fitted in the lens folders so as to prevent the lenses from falling off.
According to the diving face mask disclosed in JP1996-107948A, the annular inner frame is formed with a space so that the inner frame is partially discrete in the circumferential direction. Such construction allows the inner frame to be easily disengaged from the outer frame by deforming the space radially inward with the peripheral edge of the space held by the fingers. However, in view of the circumferentially discrete inner frame, the inner frame should be elastically deformed to be bent due to any high impact exerted externally on the lens frame during use of the mask and released from the snap engagement with the outer frame. Eventually, the inner frame should fall off together with the lens from the mask.